1. Field of the Invention
The present invention generally relates to heating, ventilation, and air conditioning (HVAC) apparatus and to cleaning apparatus, and more specifically, to a boiler cleaning apparatus and method for cleaning the external surfaces of water-tube heat exchangers.
2. Description of the Related Art
The exterior surfaces of heat exchange tubes in a heat recovery steam generator or HRSG are exposed to the byproducts of combusting fuel gases. These byproducts include soot, slag and ash that adhere to the surfaces of the tubes, creating a layer that inhibits the rate of heat transfer between the fluid (water and/or steam) flowing inside the tubes and the combusting gases flowing on the exterior of the tubes. Decrease of heat transfer efficiency demands the burning of more fuel thus diminishing the efficiency of the HRSG and increasing the costs of operation. Furthermore, the layer of byproducts can function to cause tube wall degradation leading to premature tube failure. The art would certainly welcome an efficient method for thoroughly cleaning the exterior surfaces of the tubes and apparatus for accomplishing the same. Thus, a boiler cleaning method and apparatus solving the aforementioned problems is desired.